1 . Field of the Invention
This invention relates to a rolling apparatus for a plastic film. More particularly, the invention relates to an improved rolling apparatus in which various deficiencies in a high ratio of rolling operation with conventional apparatus have been eliminated to produce plastics films of excellent quality without generating wrinkles or the like with high productivity.
2. Discussion of the Prior Art
As described, for example, in Japanese Utility Model Laid-open Publication No. 52-135465, the rolling of a plastics film is the process in which a plastic film is passed through a pair of rolls to be reduced in thickness under pressure. The rolling action is substantially caused to occur at the deformation point at which the pair of rolls are brought into contact and which point extends in the longitudinal direction of the rolls.
The above-mentioned gazette discloses that when the peripheral speeds of a pair of rolls are made different and a plastic film is fed between the rolls so as to bring the film into contact with the surface of a lower speed roll, reliable rolling action can be done at the deformation point, the rolling ratio is improved and the occurrence of wrinkles or waving of the plastic film can be avoided.
In order to carry out the rolling at a high rolling ratio with a conventional rolling apparatus, however, it is necessary to impart high pressing force to the pressure rolls, thereby causing the following problems. That is, the bursting of plastic films to be rolled is liable to occur due to the applied high pressure, the deflection of rolls is bring about due to the deformation resistance of a plastic film, and wrinkles or folds in the film is caused to occur due to the difficulty in the feeding of plastic film into the deformation point.
It is, therefore, the object of the present invention to provide a rolling apparatus for a plastic film which is capable of producing a quality plastic film with high productivity.